I'd never used it until this fall. Wow! I'm very happy with the result. I handpicked cabbage worms but there were more little, tiny worms than I could see. So, I tried the BT. Label said to spray it every week or after a heavy rain. Well, I sprayed every 10 days smashing and picking any worm I saw. There were fewer worms at each spraying. Most were tiny and obviously not doing well. Today was the third spray. I didn't see any worms at all. I figure I won't spray again until I see a worm.
I had a couple cabbage loopers on tomatoes early in the season this year. I used BT once and never had another worm on any raised bed or container plants. Well the worth $$$ in my opinion!! Next year I will use it as a preventative a couple weeks after planting outside.
